U.S. Pat. No. 5,229,201 to Blanco relates to a process for applying decals to a porous substrate. Examples of porous substrates include stone and textiles such as canvas. The patent discloses that it may be desirable to apply a gesso material such as plaster of paris or gypsum to the substrate before applying the decal. It is further disclosed that a bonding agent is applied to a surface of the porous substrate. The bonding agent may include a fast-acting solvent, a moderating agent and a sealing agent and water. The decals comprise a backing layer, a first coating layer (a downcoat), a design layer, and a second coating layer (a covercoat). Paper is included among the examples of suitable backing material and it is preferred that the backing comprise paper which is coated with a water-soluble release material.
The design layer, which comprises at least one pigment, is situated between the two coating layers. The first and second coating layers include an absorbent component and an absorbent medium overcoat, examples of which are disclosed in column 6, lines 15-65. The patent further discloses that the design layer may be wet printed by conventional wet printing techniques including screen printing or offset lithography directly onto the coating layer thereof. In the Blanco process for applying a decal to a porous surface, the backing sheet is removed from the decal by applying water to the decal to dissolve the water soluble coating and to separate the backing sheet from the first coating layer and the rest of the decal. Then, the decal including the first coating layer is applied to the bonding agent by contacting the first coating layer with the bonding agent coated porous surface to effect absorption of the first coating layer onto the porous surface.
U.S. Pat. No. 5,132,165 to Blanco relates to methods of producing a ceramic decal applied to a vitreous surface. This is accomplished, in part, by sandwiching the design layer between two glass flux layers.
U.S. Pat. No. 4,105,483 to Lin describes transferring an image onto the surface of a non-porous substrate. The image is transferred to the substrate by the application of an adhesive and pressing the surfaces together. The paper, which holds the printed image, is removed by a solvent which dissolves the paper.
U.S. Pat. No. 5,032,449 to af Strom describes a transfer process which involves preparing an image with a plastic film before separating the image from the paper. The image is then released from the paper by wetting with water. After separation, the image is kept intact by the plastic film and can be transferred onto a substrate.
U.S. Pat. No. 4,820,559 to Steelman describes a method for transferring graphics to a display surface such as a glass window. The transfer is made possible by the application of a transfer fluid, such as mineral spirits, to transfer the image from a carrier to a substrate.
U.S. Pat. No. 5,418,041 to Kent describes the decoration of ceramic articles with a ceramic ink to form a 100% ceramic product. The ceramic article is prepared by application of an oil to its surface. The image is printed on a soluble film, such as polyvinyl alcohol, and then transferred to the ceramic article using conventional water flotation or transfer printing processes. The soluble film is washed from the ceramic article.
U.S. Pat. No. 4,966,815 to Hare describes transferring a computer created image on to a fabric, such as tee shirts by printing the design on to a heat transfer sheet, and ironing the design onto the fabric.
U.S. Pat. No. 5,133,819 to Croner describes a dry process for releasing an image onto a fabric. The process is accomplished in two steps. The first step involves transferring the design to an intermediary fabric by placing an iron-on mending fabric, having a heat active adhesive coating, in contact with the source image. Second, the design is transferred to the mending fabric by activating the adhesive coating by the application of heat. In the second step, the design is transferred to the finished fabric by placing the mending fabric in contact with the receiving fabric and applying heat.
U.S. Pat. No. 5,350,474 to Yamane relates to a method for thermally transferring a design onto a receiving substrate. The process involves creating an image on a hot melt type adhesive by using a heat sensitive image transfer type recording device. The image is transferred to the receiving substrate, such as cloth, by pressing the transfer sheet and the receiving substrate together and applying heat.
The prior art processes for application of images to porous substrates and the resulting products are entirely different than the processes and products of the present invention.